How to detect the free-text from user input in slot?

[wulinjie122]

I have a use case, when user saying "I want change my job title to kdfjdkfjkdj", kdfjdkfjkdj is free text in which user may input anything they want, how can I detect acutual job title value kdfjdkfjkdj in slot and save it in variable, I tried to create entity but here it's free-text, entity can't cover all possible input from user .

user may say "I wang to change job title", bot will ask "what's the new value?", then user answer "Sales manager", or user can directly say "change my job title to sales manager"